Merge remote-tracking branch 'remotes/maxreitz/tags/pull-block-2019-08-19' into staging

Block patches:
- preallocation=falloc/full support for LUKS
- Various minor fixes

# gpg: Signature made Mon 19 Aug 2019 16:36:45 BST
# gpg:                using RSA key 91BEB60A30DB3E8857D11829F407DB0061D5CF40
# gpg:                issuer "mreitz@redhat.com"
# gpg: Good signature from "Max Reitz <mreitz@redhat.com>" [full]
# Primary key fingerprint: 91BE B60A 30DB 3E88 57D1  1829 F407 DB00 61D5 CF40

* remotes/maxreitz/tags/pull-block-2019-08-19:
  doc: Preallocation does not require writing zeroes
  iotests: Fix 141 when run with qed
  vpc: Do not return RAW from block_status
  vmdk: Make block_status recurse for flat extents
  vdi: Make block_status recurse for fixed images
  iotests: Full mirror to existing non-zero image
  iotests: Test convert -n to pre-filled image
  iotests: Convert to preallocated encrypted qcow2
  vhdx: Fix .bdrv_has_zero_init()
  vdi: Fix .bdrv_has_zero_init()
  qcow2: Fix .bdrv_has_zero_init()
  block: Use bdrv_has_zero_init_truncate()
  block: Implement .bdrv_has_zero_init_truncate()
  block: Add bdrv_has_zero_init_truncate()
  mirror: Fix bdrv_has_zero_init() use
  qemu-img: Fix bdrv_has_zero_init() use in convert
  LUKS: support preallocation

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 26 insertions, 2 deletions

diff --git a/block/vhdx.c b/block/vhdx.c
index d6070b6fa8..6a09d0a55c 100644
--- a/block/vhdx.c
+++ b/block/vhdx.c
@@ -1282,7 +1282,7 @@ static coroutine_fn int vhdx_co_writev(BlockDriverState *bs, int64_t sector_num,
                 /* Queue another write of zero buffers if the underlying file
                  * does not zero-fill on file extension */
 
-                if (bdrv_has_zero_init(bs->file->bs) == 0) {
+                if (bdrv_has_zero_init_truncate(bs->file->bs) == 0) {
                     use_zero_buffers = true;
 
                     /* zero fill the front, if any */
@@ -2075,6 +2075,30 @@ static int coroutine_fn vhdx_co_check(BlockDriverState *bs,
     return 0;
 }
 
+static int vhdx_has_zero_init(BlockDriverState *bs)
+{
+    BDRVVHDXState *s = bs->opaque;
+    int state;
+
+    /*
+     * Check the subformat: Fixed images have all BAT entries present,
+     * dynamic images have none (right after creation).  It is
+     * therefore enough to check the first BAT entry.
+     */
+    if (!s->bat_entries) {
+        return 1;
+    }
+
+    state = s->bat[0] & VHDX_BAT_STATE_BIT_MASK;
+    if (state == PAYLOAD_BLOCK_FULLY_PRESENT) {
+        /* Fixed subformat */
+        return bdrv_has_zero_init(bs->file->bs);
+    }
+
+    /* Dynamic subformat */
+    return 1;
+}
+
 static QemuOptsList vhdx_create_opts = {
     .name = "vhdx-create-opts",
     .head = QTAILQ_HEAD_INITIALIZER(vhdx_create_opts.head),
@@ -2128,7 +2152,7 @@ static BlockDriver bdrv_vhdx = {
     .bdrv_co_create_opts    = vhdx_co_create_opts,
     .bdrv_get_info          = vhdx_get_info,
     .bdrv_co_check          = vhdx_co_check,
-    .bdrv_has_zero_init     = bdrv_has_zero_init_1,
+    .bdrv_has_zero_init     = vhdx_has_zero_init,
 
     .create_opts            = &vhdx_create_opts,
 };